WEBVTT - TechStuff Stares at OLEDs 0:00:00.320 --> 0:00:02.880 Brought to you by the reinvented two thousand twelve camera. 0:00:03.200 --> 0:00:08.960 It's ready. Are you get in touch with technology with 0:00:09.039 --> 0:00:17.680 tech Stuff from how stuff works dot com. Hello everyone, 0:00:17.720 --> 0:00:20.040 welcome to tech stuff. My name is Chris Poulette and 0:00:20.079 --> 0:00:22.200 I am an editor at how stuff works dot com. 0:00:22.200 --> 0:00:25.240 Sitting across from me as always a senior writer, Jonathan Strickland. 0:00:25.480 --> 0:00:28.720 Far out in the uncharted backwaters of the unfashionable end 0:00:28.760 --> 0:00:31.320 of the western spiral arm of the galaxy lies a small, 0:00:31.400 --> 0:00:36.479 unregarded yellow sun. That's a nice quote to uh to 0:00:36.680 --> 0:00:39.360 begin this episode. That has a lot to do with light. Yes, 0:00:39.440 --> 0:00:43.519 And this comes courtesy of a little Facebook feedback you 0:00:44.880 --> 0:00:48.080 and this Facebook feedback says, Hey, guys, I love your 0:00:48.120 --> 0:00:50.600 podcast and I listened to them on my downtime. Anyway, 0:00:50.600 --> 0:00:52.879 I've done a search on how stuff works website on 0:00:53.000 --> 0:00:55.440 oh Lad, I noticed a very technical article written on 0:00:55.440 --> 0:00:57.200 the website. However, I was wondering if you guys would 0:00:57.200 --> 0:00:59.080 be willing to give your take on it. How do 0:00:59.160 --> 0:01:01.640 they stack up to L DAN plasma where the differences 0:01:01.680 --> 0:01:04.080 between the different types of old maybe explain the differences 0:01:04.080 --> 0:01:07.560 between L ed O, LAD, etcetera. Thanks, Um, Yeah, we're 0:01:07.600 --> 0:01:10.160 gonna sit there and talk a little bit about oh LEDs, 0:01:10.240 --> 0:01:12.000 what they are, what they do, how they how they 0:01:12.040 --> 0:01:16.440 are different from other technologies. Uh, and it's interesting stuff. 0:01:16.480 --> 0:01:19.680 In fact, I think by when I first started at 0:01:19.720 --> 0:01:24.840 how stuff works, Oh lads, we're still very very much 0:01:24.840 --> 0:01:28.640 in the prototype stage, and you didn't really see anything 0:01:28.760 --> 0:01:31.840 on the market at that time, the consumer market anyway, 0:01:32.080 --> 0:01:34.880 they had an o LED type screen and now they're 0:01:34.959 --> 0:01:39.319 much later in the prototype stage. But we're kidding the lads. Actually, 0:01:39.360 --> 0:01:41.240 now we're getting to the point where we're finally seeing 0:01:41.280 --> 0:01:44.960 them scaled up to large screen TVs. But for a 0:01:45.000 --> 0:01:47.720 long time, the biggest screen you're gonna get with something 0:01:47.800 --> 0:01:51.680 like eleven inches. Yeah. Well, the genesis of my joke 0:01:51.880 --> 0:01:55.280 being that people who are really interested in old technology 0:01:55.360 --> 0:01:57.680 have been waiting for them to come out for a 0:01:57.880 --> 0:02:01.040 very long time. It seems like they're uh, they've been 0:02:01.080 --> 0:02:04.480 in development of some kind for a for a long 0:02:04.520 --> 0:02:07.880 long time. They've been actually pretty common in smaller screens 0:02:07.880 --> 0:02:11.239 like smartphone screens for example. Um, they're they're really great 0:02:11.280 --> 0:02:13.120 for that. They use less energy than a lot of 0:02:13.120 --> 0:02:17.720 the other technologies and they're excellent for that. But that's 0:02:17.919 --> 0:02:21.160 you know, getting them scaled up has taken a long time, 0:02:21.200 --> 0:02:23.560 and the people who have been waiting I'm gonna buy 0:02:23.600 --> 0:02:27.240 an old TV, like, well, you know, I wouldn't hold 0:02:27.360 --> 0:02:30.440 my breath. Well, but finally they're starting to hit now. 0:02:30.520 --> 0:02:32.560 But and and also the other thing people have been 0:02:32.560 --> 0:02:34.280 waiting for, and it's one of the types we'll talk 0:02:34.320 --> 0:02:36.480 about in a little a little further in in the 0:02:36.480 --> 0:02:40.080 podcast is the flexible oh Lady, that idea of having 0:02:40.120 --> 0:02:43.560 a display that is actually malleable, that you can bend 0:02:43.560 --> 0:02:46.440 it around things. And you know, you might use that 0:02:46.480 --> 0:02:49.239 to have a foldable display. That's what a lot of 0:02:49.280 --> 0:02:51.239 people talk about. But there are other things you could 0:02:51.280 --> 0:02:54.160 use it for, Like you could use it in displays, 0:02:54.320 --> 0:02:56.800 say in a store where you've got round columns, and 0:02:56.800 --> 0:03:00.600 you could have a display wrapping around this round column. Yeah, 0:03:00.639 --> 0:03:03.639 things like that. Well, yeah, and it's uh. And that's 0:03:03.680 --> 0:03:06.600 the thing about it. I think, um, despite the fact 0:03:06.600 --> 0:03:10.000 that it's taken a while to get larger oh lad screens, 0:03:10.040 --> 0:03:12.760 the technology will be worth the way. But I think 0:03:12.800 --> 0:03:14.440 it's uh. I think it is a good idea to 0:03:14.440 --> 0:03:16.680 go ahead and talk about the similarities. And there I 0:03:16.720 --> 0:03:25.040 think three major similarities between the technologies red, green, and blue. Yeah. Light. Well, 0:03:25.080 --> 0:03:28.320 the purpose of all all the technologies we're talking about here, 0:03:28.360 --> 0:03:32.080 you know, plasma, l c D and UH you know 0:03:32.160 --> 0:03:36.560 the oh lads or LED screens and organic LED screens. UM. 0:03:36.600 --> 0:03:40.120 You know, it's it's to display information and it shows 0:03:40.240 --> 0:03:44.880 us light. UM. The trick is really how they go 0:03:44.960 --> 0:03:46.720 about doing that. And we've talked about some of the 0:03:46.720 --> 0:03:49.640 other technologies in the past, like for example, plasma uses 0:03:49.760 --> 0:03:53.960 UH gases ionized gas and basically you they show the 0:03:54.000 --> 0:03:57.000 different colors by running a charge through the gas and 0:03:57.040 --> 0:04:01.600 then look like l c D uses liquid crystals, and 0:04:01.600 --> 0:04:05.520 these liquid crystals actually form a barrier between light and 0:04:05.760 --> 0:04:08.360 the clear part of the screen, and then the l 0:04:08.440 --> 0:04:12.600 c D s, through various running an electric current through 0:04:13.000 --> 0:04:15.680 change shape and that allows light to pass through and 0:04:15.680 --> 0:04:17.920 there's some color filters in there and that's where we 0:04:18.000 --> 0:04:21.160 get the displays through that. So that's a liquid crystal display. 0:04:21.480 --> 0:04:25.280 L E D s are light emitting diodes and we've 0:04:25.279 --> 0:04:28.880 had those around for for quite some time and they're 0:04:29.000 --> 0:04:31.400 pretty efficient. They're more efficient than a lot of other 0:04:31.480 --> 0:04:34.160 forms of lighting. But an O l e D, as 0:04:34.240 --> 0:04:38.000 Chris had mentioned, is an organic light emitting diode and 0:04:38.040 --> 0:04:42.000 you might think, well, what how that huh, And it 0:04:42.040 --> 0:04:46.359 really comes down to, uh, kind of a an organic sandwich. Yes, 0:04:46.480 --> 0:04:51.239 And the thing is, uh, they're not terribly different from 0:04:51.279 --> 0:04:53.479 from the typical L E. D s, but it's it 0:04:53.560 --> 0:04:57.320 really comes down to the materials used to make that sandwich. 0:04:58.360 --> 0:05:01.040 So they're they're they're very in alright. So an O 0:05:01.279 --> 0:05:04.599 L ED it's it's solid state, all right, And it 0:05:04.720 --> 0:05:09.400 is usually between one hundred to five hundred nanometers thick, 0:05:10.560 --> 0:05:15.719 which is pretty thin. That's according to uh to most estimates. 0:05:15.760 --> 0:05:19.400 And this does change from one source to another, but 0:05:19.440 --> 0:05:22.920 it's about two hundred times thinner than a human hair 0:05:23.360 --> 0:05:26.440 in diameter. Now, human hair is actually come into a 0:05:26.520 --> 0:05:30.400 variety of diameters. It's like one person's hair might be 0:05:30.560 --> 0:05:34.920 thinner than another's. Uh. Some people have clear hair like me, 0:05:36.120 --> 0:05:40.080 My hair is invisible to the human eye. But yeah, 0:05:40.240 --> 0:05:43.560 and then you rate the two hundred it's an average, 0:05:43.600 --> 0:05:45.599 so it's two hundred times smaller than the diameter of 0:05:45.680 --> 0:05:51.719 human hair. And uh, it's they're different layers within this sandwich, right, 0:05:52.520 --> 0:05:56.680 and that's what is creating the light that you see. 0:05:56.760 --> 0:06:00.440 And there's the basics the the bread on the sandwich, 0:06:00.480 --> 0:06:05.160 if you will, is our pair of electrodes. Right, You've 0:06:05.160 --> 0:06:07.239 got your cathode and you've got your anode. Now, technically 0:06:07.240 --> 0:06:10.120 you also have the substrate. The substrate is the foundation 0:06:10.279 --> 0:06:14.440 that the lad sits upon, So substrate is also part 0:06:14.480 --> 0:06:17.000 of this, but I'm looking mostly at the components that 0:06:17.040 --> 0:06:21.320 actually make the old work. Right. So, yeah, you've got 0:06:21.320 --> 0:06:23.799 the cathode and the anode, and you've got the jobs 0:06:23.839 --> 0:06:25.760 of the cathode and the anode are to create a 0:06:25.760 --> 0:06:28.919 circuit for electricity to flow through, right right, The electrons 0:06:28.920 --> 0:06:31.520 flow from one to the other, from the cathode to 0:06:31.720 --> 0:06:34.000 the anode. And in a way you have to kind 0:06:34.000 --> 0:06:38.200 of think of this in uh interesting terms, like, so 0:06:38.360 --> 0:06:46.200 cathode is injecting negative particles into this o led sandwich. Yes, 0:06:46.480 --> 0:06:49.080 I am positive that they are negative electrons, is what 0:06:49.240 --> 0:06:54.000 cathodes are putting into their The anode is creating well 0:06:54.000 --> 0:06:58.360 what we call them electron holes. They're positive. It's they 0:06:58.480 --> 0:07:01.440 turn an element into a positively charged element. They actually 0:07:01.520 --> 0:07:04.239 pull electrons out of it and so now it's positively charged. 0:07:04.520 --> 0:07:06.839 So that means that the electrons coming from the cathode 0:07:06.839 --> 0:07:11.600 are attracted toward the anode. Side. Hey, you're pretty cute, 0:07:11.760 --> 0:07:13.920 and so it has to pass through the other layers 0:07:13.920 --> 0:07:17.680 of the sandwich. And there are two or three other 0:07:17.760 --> 0:07:20.400 layers depending on the type of o ledge you're looking at, 0:07:20.920 --> 0:07:25.440 but really the two layer is the most common, so 0:07:25.840 --> 0:07:29.200 I'll just stick with that. So you've got your emissive layer, 0:07:29.440 --> 0:07:33.160 this is the layer that actually emits light, and you 0:07:33.240 --> 0:07:37.680 have your conductive layer, which is the layer that attracts 0:07:37.680 --> 0:07:41.960 the electrons through the other materials. So if we're looking 0:07:41.960 --> 0:07:44.760 at top to bottom and the bottom is the substrate, 0:07:45.520 --> 0:07:48.720 then the top layer is your cathode. Next down you 0:07:48.720 --> 0:07:50.920 have your emissive layer, that's where the light comes through. 0:07:51.560 --> 0:07:53.720 Then you have your conductive layer that's what's pulling the 0:07:53.760 --> 0:07:56.800 electrons down. Then you have the anode layer. That's what's 0:07:56.880 --> 0:08:00.000 really pulling the electrons down. It's what's allowing the conductive 0:08:00.040 --> 0:08:02.520 layer to pull these electrons through. And then you have 0:08:02.560 --> 0:08:09.080 the substrate. So, uh, why are we getting light? Boy? 0:08:09.240 --> 0:08:13.880 This this gets into some interesting physics here. Okay, So 0:08:13.960 --> 0:08:16.680 you've got the electrons coming through from one side, you've 0:08:16.680 --> 0:08:19.480 got the electron holes coming through from the other side. 0:08:19.800 --> 0:08:21.880 So in a way, you can think of negative charge 0:08:21.920 --> 0:08:24.640 and positive charge. I know that sounds weird, but just 0:08:24.760 --> 0:08:28.480 go with me here. And when those two meet, the 0:08:28.520 --> 0:08:33.080 molecule that they meet at becomes UH actually drops an 0:08:33.080 --> 0:08:36.959 electron into that positive hole and as a result there 0:08:37.040 --> 0:08:41.160 is a difference in energy. It releases some energy as 0:08:41.200 --> 0:08:44.240 a result of that that reaction, and that energy is 0:08:44.240 --> 0:08:47.040 released in the form of a photon. And we've talked 0:08:47.040 --> 0:08:50.680 about this before about how if you excite an atom, 0:08:51.280 --> 0:08:52.880 you know, by telling you it's going to this new 0:08:52.880 --> 0:08:56.520 world or something, and the electrons move to a higher 0:08:56.600 --> 0:08:59.280 energy state. When those electrons move back down, once that 0:08:59.440 --> 0:09:02.640 energy has has been removed from the system, once the 0:09:02.679 --> 0:09:05.640 electrons moved back down, they have to release that extra energy, 0:09:05.720 --> 0:09:07.880 and they often will do this in the form of photons, 0:09:07.920 --> 0:09:12.280 which we perceive as light. That's exactly what's going on here. Actually, 0:09:12.320 --> 0:09:15.480 I saw a great video on this UH at m 0:09:15.480 --> 0:09:19.880 I t S site where a professor was explaining how 0:09:19.880 --> 0:09:23.360 oh LED's work by shocking the heck out of a pickle. 0:09:24.640 --> 0:09:27.480 He had a had a cathode and an anode um 0:09:28.400 --> 0:09:30.880 attached to a pickle and was running a very high 0:09:30.880 --> 0:09:33.560 electric current through it, which was making the pickle glow. 0:09:34.440 --> 0:09:36.160 And it was this is what was happening. You had 0:09:36.200 --> 0:09:38.480 the positive charge in the negative charge meeting and the 0:09:38.520 --> 0:09:42.599 molecules where it met at that's where it was releasing 0:09:42.640 --> 0:09:45.720 this electron and uh and and releasing a photon or 0:09:45.880 --> 0:09:48.000 or it was the electron states were moving down and 0:09:48.040 --> 0:09:50.000 the photons were being released, and that's why we were 0:09:50.000 --> 0:09:55.360 getting light. Um. Pretty cool. Actually, I kind of wanted 0:09:55.400 --> 0:09:57.240 to build one, except for the fact that I'm sure 0:09:57.280 --> 0:10:01.439 I would probably electric you myself. For a second there, 0:10:01.440 --> 0:10:05.160 I thought you were girk in my chain. Anyway, So 0:10:05.400 --> 0:10:07.640 when we're talking about electricity, we're not talking about a lot. 0:10:08.760 --> 0:10:11.560 These are pretty efficient, so we're talking in a realm 0:10:11.559 --> 0:10:14.439 of just a few volts that are needed in order 0:10:14.480 --> 0:10:18.800 to excite these molecules so that they emit light. That's 0:10:18.840 --> 0:10:21.400 one of the major benefits of old screens is that 0:10:21.440 --> 0:10:24.559 they don't require as much electricity as some others. You know, 0:10:24.600 --> 0:10:28.240 of course, plasma TVs are are notorious for using a 0:10:28.240 --> 0:10:30.880 lot of electricity. Well, you have to keep pouring in 0:10:30.960 --> 0:10:35.440 electricity to keep that gas ionized. So yeah, plasma display 0:10:35.559 --> 0:10:39.480 is not They've gotten a lot better last years, but 0:10:39.679 --> 0:10:42.760 is it is by its very nature, is not the 0:10:42.800 --> 0:10:47.880 most environmentally friendly way of creating a television. Not that 0:10:47.960 --> 0:10:50.679 TV is terribly environmentally friendly no matter how you do it, 0:10:50.760 --> 0:10:53.920 but but it's it's less So yeah, plasma has a 0:10:53.920 --> 0:10:58.640 reputation for being for being less energy friendly. So yeah, 0:10:58.679 --> 0:11:01.719 there there there have been some better ones, but still uh. 0:11:01.760 --> 0:11:07.160 And those two different layers of molecules are are are organic, 0:11:07.520 --> 0:11:13.040 but they're organic plastic. It's pretty cool organic plastic like 0:11:13.080 --> 0:11:19.400 poly anelyin and polyfluorine. Okay, all right, you know, Pollyanna, 0:11:19.920 --> 0:11:22.520 you know when you when you say we're organic plastic, 0:11:22.559 --> 0:11:25.720 that sort of sounds like it's oxymoronic, like you know 0:11:25.920 --> 0:11:31.120 organ chuah wa Um. Well that that's actually um. We 0:11:31.120 --> 0:11:34.000 should talk about to the different types of oh leads 0:11:34.040 --> 0:11:37.520 because there are r G b OH lead screens and 0:11:37.559 --> 0:11:41.320 then there's the white lead screen UM, which sort of 0:11:41.400 --> 0:11:46.680 uses a color sandwich to UM and by by activating red, green, 0:11:46.800 --> 0:11:51.160 and blue, you get white UM. And uh you know 0:11:51.440 --> 0:11:54.400 those the red, green, and blue are are pressed together 0:11:54.679 --> 0:11:58.520 in the same pixel. So by doing that you can 0:11:58.600 --> 0:12:03.080 you can have the have basically a pure white UM 0:12:03.320 --> 0:12:06.640 and it's it. It works a little slightly differently than 0:12:06.800 --> 0:12:11.520 than the others simply because of that UM there are 0:12:12.240 --> 0:12:14.920 people say that it has a longer life than the 0:12:15.000 --> 0:12:19.920 traditional OH lead screens UM, but that is supposed to 0:12:19.920 --> 0:12:22.920 be one of the advantages of it. UM and it's 0:12:22.920 --> 0:12:26.840 also possible to, uh to scale the white OH lead 0:12:26.880 --> 0:12:30.360 screens up a little easier from what I understand. Yeah, 0:12:30.360 --> 0:12:34.120 it's also been talked about as a potential replacement for 0:12:34.160 --> 0:12:37.440 things like fluorescent lights, where not just for displays, but 0:12:37.480 --> 0:12:41.559 for actual lighting, because that's it's even more efficient than 0:12:41.640 --> 0:12:44.680 fluorescent lighting is. And uh, you know you don't have 0:12:44.720 --> 0:12:49.360 that mercury that you gotta worry about that's in fluorescent lights. Yeah, guys, 0:12:49.520 --> 0:12:51.920 if you have those little fluorescent bulbs, which are you know, 0:12:51.960 --> 0:12:54.880 more energy efficient that incandescent bulbs, will good on you, 0:12:54.960 --> 0:12:57.760 but be very careful with them, yes, because those suckers 0:12:57.840 --> 0:13:01.160 do contain some very toxic chemicals in them that can 0:13:01.200 --> 0:13:03.920 be very dangerous. Yes, you do not want to bust them, right, 0:13:04.000 --> 0:13:07.960 So the O lead lights might be a nice alternative 0:13:08.000 --> 0:13:10.800 to that, you know, if if it's efficient enough so 0:13:10.840 --> 0:13:14.520 that they make economic sense to the consumer, because you know, 0:13:14.520 --> 0:13:17.320 you gotta worry about that, uh, And also the fact 0:13:17.320 --> 0:13:20.840 that they don't have these toxic chemicals necessarily inside them. 0:13:20.880 --> 0:13:23.000 If they are just as efficient or more so, then 0:13:23.400 --> 0:13:26.240 makes perfect sense to go and switch to it. Yeah. 0:13:26.240 --> 0:13:29.760 There are actually several different types of oh lad screens 0:13:30.360 --> 0:13:33.360 and no lead displays. We talked about the foldable oh lads. 0:13:33.400 --> 0:13:37.400 Now these are using a substrate that is flexible. So 0:13:37.520 --> 0:13:39.679 you know, your typical substrate. When I think of substrate, 0:13:39.720 --> 0:13:41.440 I think of something that is that is, you know, 0:13:41.840 --> 0:13:45.080 pretty solid, or sometimes it can be a little brittle 0:13:45.200 --> 0:13:48.400 or whatever, but it doesn't bend. It's not bendy bindy. Right. Well, 0:13:48.440 --> 0:13:50.600 the the idea of being that you're going to build 0:13:50.679 --> 0:13:55.480 your circuit material on top of this material. So I 0:13:55.480 --> 0:13:58.200 mean you're this it's a board, so you you know, 0:13:58.280 --> 0:14:00.720 you're I'm going to add the stuff to it, right, Yeah, 0:14:00.840 --> 0:14:03.160 Usually you want something that's fairly solid, although you know, 0:14:03.440 --> 0:14:06.920 obviously for other applications you would need something that's flexible. 0:14:06.960 --> 0:14:09.880 Let's say that you want to create a display on 0:14:10.280 --> 0:14:13.800 say a jacket, which might very well be something not 0:14:13.840 --> 0:14:16.920 necessarily that the consumer would ever see. But let's say 0:14:16.920 --> 0:14:20.520 an advertising company creates this, uh, this type of of 0:14:20.720 --> 0:14:23.160 jacket that can have a flexible screen on the back 0:14:23.160 --> 0:14:25.520 of it, and then next thing, you know, You've got 0:14:25.560 --> 0:14:29.200 this new way for at trade shows where people can 0:14:29.280 --> 0:14:34.560 show off cool technology and it's literally playing on their backs. Um. 0:14:34.720 --> 0:14:37.120 I mean, I could even imagine it going so far 0:14:37.240 --> 0:14:40.520 as to, let's see, you've got a courier service and 0:14:40.640 --> 0:14:44.280 you are sponsored, and they run ads on your back 0:14:44.480 --> 0:14:49.360 as you're you're a bike courier. I look forward to 0:14:49.400 --> 0:14:52.359 seeing that. I look forward to seeing all the accidents 0:14:52.360 --> 0:14:54.320 that will happen as a result of people turning their 0:14:54.360 --> 0:14:56.440 heads to see what to watch. Yeah, they're like, I'm 0:14:56.440 --> 0:14:58.240 want to follow this guy another mile. I have to 0:14:58.280 --> 0:15:01.200 see how this turns out. Clearly that if you did that, 0:15:01.200 --> 0:15:05.200 you'd have to make very visually stunning types of ads 0:15:05.240 --> 0:15:07.920 that don't need any audio. That would be that that 0:15:07.960 --> 0:15:11.480 would be the real challenge there. Look, I'm just trying. 0:15:11.520 --> 0:15:14.040 I'm just I'm just trying to create some jobs out there. 0:15:14.480 --> 0:15:16.480 That's what I'm trying to do. Okay, But you also 0:15:16.520 --> 0:15:21.160 have you have your passive matrix. Oh lad, Now passive matrix, 0:15:21.200 --> 0:15:23.440 Oh lads. You know we talked about the cathodes and 0:15:23.480 --> 0:15:27.320 the anodes. Well that's not necessarily a sheet on top 0:15:27.320 --> 0:15:29.320 of you know, when I said sandwich, it sounds like 0:15:29.320 --> 0:15:33.560 you're talking about solid sheet, that's not necessarily the case, 0:15:33.560 --> 0:15:37.200 although that can be done a passive matrix. Oh lad. 0:15:37.640 --> 0:15:39.960 What it does is it it arranges the cathodes and 0:15:39.960 --> 0:15:43.960 anodes into strips. And one says strips are vertical and 0:15:44.000 --> 0:15:45.960 the other sets strips are horizontal. So you could think 0:15:45.960 --> 0:15:48.920 of it like all the anodes are streets and all 0:15:48.920 --> 0:15:52.880 the cathodes are avenues. So at these intersections where the 0:15:52.880 --> 0:15:55.560 cathode and anode meat, that's where you have your pixels, 0:15:55.920 --> 0:15:58.400 and your pixels of course, that's the point of light. 0:15:58.520 --> 0:16:00.320 So when you talk about how many picks soles that 0:16:00.400 --> 0:16:02.760 display has at so many points of light it is 0:16:02.800 --> 0:16:06.880 capable of displaying at one time more than that. It 0:16:06.920 --> 0:16:10.400 would be a very low resolution television. Uh. The So 0:16:10.840 --> 0:16:12.680 this is one way of doing that where you have 0:16:13.240 --> 0:16:15.640 the just at the intersections of these strips, that's where 0:16:15.640 --> 0:16:20.880 the pixels are uh. Not terribly efficient compared to other 0:16:20.920 --> 0:16:25.200 oh lads and uh And also for all of these screens, 0:16:25.560 --> 0:16:29.040 if you're wondering about controlling brightness, that's a function of 0:16:29.040 --> 0:16:31.880 how much electricity is flowing through the system. If you're 0:16:31.880 --> 0:16:33.960 pouring more juice into it, it's going to be brighter, 0:16:34.240 --> 0:16:37.600 less juice not as bright, which makes sense. Uh. Next 0:16:37.640 --> 0:16:40.520 we have the active matrix, oh lad, and this has 0:16:40.560 --> 0:16:43.560 a full sheet of the cathode and and it's sort 0:16:43.560 --> 0:16:47.480 of like the sandwich example I was giving earlier. So 0:16:48.600 --> 0:16:53.440 in this case, there is a film transistor that is 0:16:53.720 --> 0:16:58.320 uh gotta. It's an anode layer overlay, and that's what 0:16:58.480 --> 0:17:02.160 forms the matrix. Uh, not the kind that NEO goes 0:17:02.240 --> 0:17:05.080 through with all the zeros and ones, but this in 0:17:05.160 --> 0:17:08.600 the it forms the same feature as the intersections on 0:17:08.680 --> 0:17:13.720 the passive matrix. Oh lead, tank, I need an exit. O. Gosh, wow, 0:17:14.320 --> 0:17:16.080 out of all of those, you know, I'm surprised you 0:17:16.080 --> 0:17:22.639 didn't say I know kung fu or just whoa uh 0:17:22.880 --> 0:17:25.240 you got your transparent Oh lads, Now these are really 0:17:25.400 --> 0:17:28.720 super cool. Like everything every single element in this oh 0:17:28.760 --> 0:17:33.800 lead is transparent. So when light is uh is flowing 0:17:33.800 --> 0:17:38.520 through this system, then you see it projected within a 0:17:38.560 --> 0:17:41.560 clear screen, and when it's not, you can just look 0:17:41.600 --> 0:17:43.840 through the screen. Now, this is used in things like 0:17:43.880 --> 0:17:49.200 heads up displays. So you know, you're talking exactly, flying 0:17:49.200 --> 0:17:51.320 a plane, driving a car, whatever, If you've got a 0:17:51.359 --> 0:17:54.399 heads up display that can show within the uh the 0:17:54.400 --> 0:17:58.520 wind screen or or cockpit screen or whatever. That is 0:17:58.920 --> 0:18:03.479 very likely a transparent oh lead. I've also seen this 0:18:03.720 --> 0:18:08.520 used in smart windows, which was something new. I mean 0:18:08.560 --> 0:18:10.600 I had heard about smart windows before, but it was 0:18:10.640 --> 0:18:13.480 the first time I had seen one. Was at CS 0:18:14.119 --> 0:18:16.600 where I think it was Samsung that had it, where 0:18:16.600 --> 0:18:19.800 it's a smart window that could display information and it 0:18:19.880 --> 0:18:22.639 could do things that give you like little information like 0:18:22.800 --> 0:18:25.680 news items or the weather or whatever. Although when you're 0:18:25.680 --> 0:18:28.240 looking out a window, if you need a weather report, 0:18:28.280 --> 0:18:34.080 when you're looking out a window, you're not being terribly observant. Well, 0:18:34.119 --> 0:18:35.919 it might be nice to know what the temperature is 0:18:35.960 --> 0:18:40.000 going to be open the window. Oh okay, alright, so 0:18:40.040 --> 0:18:44.160 you're looking at the future forecast. Alright, fine, fine, yeah, 0:18:44.440 --> 0:18:50.480 you know, all right, okay, and I withdraw my objection. 0:18:51.240 --> 0:18:55.400 Uh what about active matrix I talked about those. That's 0:18:55.440 --> 0:18:56.640 the one with the that's the one with a thin 0:18:56.680 --> 0:18:59.680 film transistor. Do you want I just okay? They used 0:18:59.680 --> 0:19:01.840 as a lot in the phones. So oh yes, yes, yes, yes, 0:19:01.880 --> 0:19:04.160 that's the one that does have that thin film transistor 0:19:04.160 --> 0:19:06.000 I was talking about. That's the one that ends up 0:19:06.040 --> 0:19:11.080 taking the place of the intersections. The thin film transistor 0:19:11.119 --> 0:19:13.959 itself has the connections on it on the anode side 0:19:14.280 --> 0:19:16.760 where it activates where the pixels are, and these pixels 0:19:16.800 --> 0:19:20.399 are active. The fact that they are so thin is 0:19:20.400 --> 0:19:23.399 the benefit when you're talking about these electronic devices. But 0:19:23.960 --> 0:19:26.320 it makes it so much easier to uh, you know, 0:19:26.359 --> 0:19:31.600 fit it into these tablet form factors and smartphones. Yeah, 0:19:31.600 --> 0:19:34.200 if we were still using if we were using things 0:19:34.200 --> 0:19:37.840 like l c D technology for all of these devices, 0:19:38.440 --> 0:19:42.040 they would be significantly or at least noticeably larger, like 0:19:42.119 --> 0:19:45.280 thicker and and somewhat heavier, and I mean heavy being 0:19:45.320 --> 0:19:47.480 a relative thing. But in the case of it, every 0:19:47.480 --> 0:19:50.200 ounce counts. Yeah, in a tablet or something like that, 0:19:50.320 --> 0:19:53.320 you know, if it adds six ounces. Yeah. There's one 0:19:53.359 --> 0:19:55.879 more type of O lead talk about, which is the 0:19:55.920 --> 0:19:59.960 top emitting OH lead. And this has got a substrate 0:20:00.200 --> 0:20:04.560 that is either opaque or reflective, and they are often used. 0:20:04.600 --> 0:20:07.600 This is often uh like this, this is just one 0:20:07.880 --> 0:20:10.960 subtype of O lead. It can actually be combined with 0:20:11.080 --> 0:20:13.760 another type of A lead. So in other words, that 0:20:13.800 --> 0:20:17.560 active matrix old we were just talking about, that method 0:20:17.720 --> 0:20:21.399 of display could be combined with the top admitting OH lead. Uh. 0:20:21.440 --> 0:20:23.280 And this is something that's often used in things like 0:20:23.320 --> 0:20:26.560 smart cards, so lots of different applications of oh leads, 0:20:26.640 --> 0:20:32.600 not just uh displays on phones or UM or TVs 0:20:32.720 --> 0:20:35.800 or or even you know, computer monitors that kind of thing. Uh. 0:20:36.000 --> 0:20:39.800 It's interesting because even though it sounds pretty complex, really 0:20:39.880 --> 0:20:45.040 it's simpler than things like l c D technology. It is. 0:20:45.160 --> 0:20:49.960 It is much simpler in the grand scheme of things, um, 0:20:50.000 --> 0:20:52.680 even though it's more advanced technology, and it's taken years 0:20:52.680 --> 0:20:55.760 to kind of get the prototype, the manufacturing process efficient 0:20:55.880 --> 0:20:59.880 enough so that we can build screens that are at 0:21:00.080 --> 0:21:03.959 the size that we're used to. Even so, you know, 0:21:04.160 --> 0:21:07.440 we have mentioned that, yes, there are television screens coming out, 0:21:07.640 --> 0:21:11.240 like large ones TVs that use o LAD displays. They 0:21:11.280 --> 0:21:15.600 are incredibly thin, like to the point where you can't 0:21:15.640 --> 0:21:17.159 even really get a good picture of them when you 0:21:17.160 --> 0:21:20.480 look at them in a profile. Um. However, they also 0:21:21.000 --> 0:21:23.960 tend to cost a princely some Yes, that's what I 0:21:24.040 --> 0:21:26.200 was getting at, is that we have reached the point 0:21:26.200 --> 0:21:29.160 where the manufacturing process has allowed us to build these, 0:21:29.600 --> 0:21:34.280 but they're still prohibitively expensive. For I'd say the majority 0:21:34.400 --> 0:21:37.520 of the consumer market. New TV is likely to cost 0:21:37.600 --> 0:21:41.199 you several thousand dollars we're talking like ten grand, easy, 0:21:41.320 --> 0:21:46.680 ten thousand dollars for oh lad screen easy. Um that 0:21:46.680 --> 0:21:49.399 that's a lot of money for a new television set. 0:21:49.800 --> 0:21:52.119 I would not be prepared to spend that much on 0:21:52.160 --> 0:21:55.880 a TV. And if you're talking about using a competing 0:21:55.880 --> 0:21:59.720 technology that costs say one fifth of that, you know 0:22:00.200 --> 0:22:03.240 or or or yeah or less depends I think the 0:22:03.320 --> 0:22:06.320 last thing. So for example, I I purchased an l 0:22:06.359 --> 0:22:10.439 E D l c D h D t V for 0:22:11.480 --> 0:22:15.400 um way less than that, like less than a tenth 0:22:15.480 --> 0:22:17.920 of that. And so you look at that and you're 0:22:17.960 --> 0:22:23.080 you're saying, yeah, the the technology, the display technology is 0:22:23.119 --> 0:22:27.160 clearly superior in that, clearly clearly hauh, in that it's 0:22:27.320 --> 0:22:30.840 got a very crisp picture. The colors are are very 0:22:30.880 --> 0:22:34.920 true true blacks. Yes, because you don't have that backlighting, 0:22:35.680 --> 0:22:38.159 just like plasma. Plasma does not have backlighting, but l 0:22:38.200 --> 0:22:40.600 c D does, which is why if you've ever had 0:22:40.760 --> 0:22:42.560 l c D television, new mine is an l c 0:22:42.720 --> 0:22:45.400 D t D. It's just backlit by l E D S. Yeah, 0:22:45.480 --> 0:22:47.879 so that's why l E D l c D. Yeah. 0:22:47.920 --> 0:22:50.639 So when you both but but if you're watching in 0:22:50.640 --> 0:22:53.520 a dark room and it's a scene that is like 0:22:53.600 --> 0:22:57.920 someone walks into a pitch black room in a house, 0:22:58.080 --> 0:23:00.800 or there's suddenly like a blindfolds put on or whatever. 0:23:01.080 --> 0:23:03.040 You start to notice like, wait a minute, my my 0:23:03.080 --> 0:23:06.480 screen is actually kind of glowing, like it's not really black, 0:23:06.800 --> 0:23:08.920 it's just really dark and I can see that there's 0:23:09.000 --> 0:23:12.040